The present invention is directed to an electrical plug-type connector having a housing with at least one contact chamber for a pluggable contact element, wherein the contact element comprises at least first and second catch tongues that project arrow-like outward opposite to the plug-in direction, the contact chamber having an interlock mechanism for the contact element that defines a primary latching position of the interlock mechanism and the contact element can be introduced unimpeded into the contact chamber.
U.S. Pat. Nos. 4,583,805 and 4,660,915, whose disclosures are incorporated herein by reference thereto and both of which claim priority from German Application 32 47 022, disclose a plug-type connector having a housing with a contact chamber for a pluggable contact element. In order to achieve a durable positional fixing of the inserted contact element in the contact chamber, the known plug-type connector, first, comprises a primary securing means which has the contact element being provided with only one catch tongue that engages behind a stationary catch edge in the contact chamber in the plugged condition. In addition, a plastic frame having interlocking arms that can be brought into engagement with the contact element is provided as a secondary securing means. The frame can be fixed on the housing at the introduction side for the contact element so that the interlock arms are introduced into the contact chamber in the plug-in direction and fix the contact element therein in a clamping fashion.
Plug-type connectors having interlock devices are also commercially obtainable wherein differently fashioned slides that act transversely relative to the plug-in direction are employed. These, however, do not form a movable contact chamber wall, but act in addition to the usual, stationary contact chamber walls. In practice, all known interlock mechanisms exhibit at least one of the following problems.
In many instances, the secondary securing means can be actuated without the primary securing means having been engaged into its provided, ultimate position. The secondary securing element is often only clamped between contact elements and contact chamber walls without engaging behind the contour of the contact. Given secondary securing means provided for that purpose, such an engagement is also not assured with adequate dependability in view of the errors that can occur over and over again in non-automated, manual assembly and in view of the manufacturing tolerances. When the securing occurs only on the basis of the clamping force, then the contact element can be damaged. A dependable electrical contact may not be obtained when, as is possible in many designs, an incorrectly plugged or, respectively, secured contact can be pressed out of the housing when plugging in the blade contacts of the plug-type connector. Given standard contact elements having double-sided catch tongues, moreover, it can easily occur that only a single-sided interlock occurs. Such malfunctions cannot be reliably discovered with known testing methods.
Over and above this, the interlock elements in many solutions are under stress so that in their ultimate position, the retainer elements can no longer spring laterally back after some time after releasing the secondary securing means and disassembly of the contact is, therefore, hardly possible without damage to the device. As a consequence of the more and more compact structure of the plug-type connectors, the space for secondary securing means is becoming more and more constricted so that the integration space for most existing solutions may not be available. Finally, known interlock solutions also present problems in conjunction with water-tight housings and in conjunction with the outlay that is often required in terms of injection molding.